Q140419

Picture of the Day · NASA

Pathfinder on Mars

2026-07-04

On July 4th, 1997, using its own array of fireworks, a parachute, and a cocoon of airbags, the Mars Pathfinder spacecraft bounced like a giant beach ball at least 15 times before it came to rest on the surface of Mars at 10:07 AM Pacific Daylight Time. After its then novel airbag-assisted landing sequence was completed, Pathfinder transmitted this color mosaic to mission operators on Earth. In the scene from another world, the Mars Sojourner robot rover is visible in the foreground, crouched on top of the unfolded Pathfinder. About the size of a large house cat, the six-wheeled, solar-powered Sojourner became the first successful Martian rover. Surrounding Pathfinder are deflated airbags and the rock-strewn terrain of the Ares Vallis floodplain. In the distance Martian hills appear against a dusty brownish sky. The Pathfinder lander was subsequently renamed the Carl Sagan Memorial Station.

via NASA APOD

Key facts

Discovered by

Y. Väisälä

Discovery site

Turku Obs.

Discovery date

18 September 1939

Named after

Joensuu (Finnish town)

Alternative designations

1939 SB · 1931 EL, 1933 QO · 1936 DG, 1958 DH 1

Minor planet category

main-belt · ( outer )

Observation arc

85.95 yr (31,395 days)

Aphelion

3.4881 AU

Perihelion

2.7300 AU

Semi major axis

3.1090 AU

Orbital period sidereal

5.48 yr (2,002 days)

Mean anomaly

88.699 °

Mean motion

0° 10 47.28 / day

Inclination

12.687°

Longitude of ascending node

347.72°

Argument of perihelion

2.7611°

Dimensions

39.37 ± 12.22 km , 42.79 ± 1.1 km , 42.83 km (derived) , 44.87 ± 0.78 km , 45.056 ± 0.291 km , 49.394 ± 0.502 km

Synodic rotation period

9.276 ± 0.007 h

via Wikipedia infobox

Wikidata facts

Instance of

asteroid

Named after

Joensuu

Followed by

Q140426

Follows

1523 Pieksämäki

Parent body

Sun

Minor-planet group

asteroid belt

Diameter

45.056

Orbital period

2004.157120495938

via Wikidata · CC0